distributor install

Just make SURE the engine is at TDC on the COMPRESSION stroke NOT the exhaust!...Mark

Yeah, thanks. I think I got that covered. I watched the rockers, one down, then up, then the other down and up (so both valves closed = BDC) then turned motor over 180 degrees, felt for the compression with my finger in the hole.

I'll double/triple check that again anyways, but I'm wanting to know about the procedure for setting my timing points at the balancer and the distributor install/rotor position.

It's not rocket science, it's just the last time I did this was on my 68 GTO maybe 1985?

Back then we just went for it, found out the hard way when your 180 off, with THE biggest backfires ever! lol

quote:

Originally posted by 1Rocketship:
Just make SURE the engine is at TDC on the COMPRESSION stroke NOT the exhaust!...Mark

Hello Mike; Not to be a "Party Pooper" but there is NO time that both valves are CLOSED at (BDC).

ONLY time BOTH valves are CLOSED is at TDC!...Mark

Well, there's the time where one rocker pushes a valve down and up, and then the other rocker immediately pushes the other valve down and back up (yes, there's a bit of overlap there, you are correct-this is BDC) but then 180 degrees from there is TDC.

Here's an informative article, discussing "overlap/valve timing" & how the exhaust valve/s OPEN prior to BDC on the Power stroke...Mark

If engine performance is your thing, or you are an automotive hobbyist, then you are most likely not afraid of swapping cams in your engine. However, the trick to making your car faster is not just replacing stock engine parts with performance engine part, but replacing it with the right performance parts. This is where your understanding of valve timing becomes crucial in selecting the proper cam. To help you better understand valve timing, this page will cover blow down overlap and the ram effect.

BLOW DOWN
On the power stroke, the combustion pushes the piston down in the cylinder. During this stroke, it is necessary to open the exhaust valve before the piston gets to the bottom of the cylinder. This will allow the excess pressure in the cylinder to "vent out" just before the piston reaches the bottom of the stroke. The term "Blow Down" is used to describe this event.

Timing the exhaust valve in this manner assures no pressure is left in the cylinder to push against the piston on the exhaust stroke. Otherwise, there could be 20 PSI (or so) pushing against the piston as it starts up the cylinder. This would require some of your engine's power just to push the exhaust out of the cylinder!

High RPM engines need to have the exhaust valve open sooner so the pressure has a better chance to exit the cylinder. However, at lower RPMs, opening the exhaust valve too soon means you didn't take full advantage of the power stroke. The Engine Analyzer Pro software is a good program to use for experimenting with blow down because you can quickly try different valve timing and see the cylinder pressure on your computer screen. That way you are better informed before you buy those performance engine parts.

OVERLAP
As the engine cycles, there is a period when both the intake and exhaust valves are open at the same time. This valve timing is known as "overlap." Think of this as the exhaust and intake cycles overlapping each other.

The valves are timed so the intake valve opens slightly before the piston reaches top dead center (TDC) on the exhaust stroke. Likewise, the exhaust valve is timed to close just after the piston starts down on the intake stroke.

The objective of overlap is for the exhaust gas which is already running down the exhaust pipe, to create an effect like a siphon and pull a fresh mixture into the combustion chamber. Otherwise, a small amount of burned gasses would remain in the combustion chamber and dilute the incoming mixture on the intake stroke. This valve timing is a product of the cam's duration and separation specs. For more information on these cam specs see the Cam Specs & Effects page.

The science involved with overlap is quite complex. Pressures, runner lengths, temperature, and many other aspects influence how well the overlap effect works. The advantage to using software like Engine Analyzer Pro is that the software does all of the calculations for you. Simply enter a different duration and separation in the computer and the software will show you whether or not to expect more power from your engine.

RAM EFFECT
When the piston reaches the bottom of the cylinder on the intake stroke, the intake valve doesn't immediately close at this point. The intake valve remains open even though the piston is starting up the cylinder on the compression stroke. The expression "ram effect" is used to describe this event.

Timing the intake valve in this manner allows an additional amount of fresh mixture to be rammed into the cylinder. The effect is very similar to water hammer in plumbing. What happens is that during the intake stroke the fresh mixture is running fast enough down the intake manifold and into the cylinder that it can not instantly stop when the piston stops at the bottom of the intake stroke. Just like the water hammer effect, the incoming mixture is rammed into the cylinder even though the piston may be starting up on the compression stroke.

High RPM engines can have the intake valve remain open longer to take advantage of this ram effect. However, at low RPMs, the ram effect is not strong enough and the piston will start to push the fresh mixture back out of the cylinder. Of all the different valve timing effects, this one can have the greatest impact on your engine's performance. By advancing or retarding the cam or trying a different camshaft in the Engine Shop or the Engine Analyzer Pro software, you will know if you have the correct valve timing to take advantage of the ram effect. Don't guess which performance engine parts to get, use our software and get the right parts the first time.

Thanks for the info.

I already had kind of a base knowledge of all that, but you explained it very well.

On my engine, it ran like a bat out of hell, just circumstances and bad luck and omissions of some important facts have resulted in my now spending extra thousands getting the car back running, but it ran well before it stopped, and nothing has changed, so I expect once I get it all back together that it should run as it did before. I found a magazine where Roger dynoed this engine to over 8000 rpm, I know it's a runner.

I;ve still got a hundred small things, and a few big things to do, but we are very close to getting hr back running and tearing up the road again.

My novice experience: You need to apply a bit of Kentucky windage when installing the dizzy. As the dizzy gear meshes with the cam gear, the shaft (rotor) turns as the dizzy seats. If you want it to be on the #1 plug when seated, you have to point the rotor ahead of that distributor cap location so it will rotate to the right position when fully seated. Sometimes it takes a few tries. Before removal I had marked my dizzy flange and the block so I could install it back in the original place so the leads and vacuum advance stuff was facing the right direction. The smart guys on this forum probably have a slicker way of doing that.

Hello Robbie; The "Kentucky Windage" line, made me chuckle.

Wonder how many know that phrase?

Pantera Doug thinks it's what a guy from Kentucky does after eating too much Chili! .

Excellent advice by the way, as the spiral cut distributor gear drops down further into meshing with the cam gear the initial point of contact/gear engagement will change thus altering the final positioning point with which the rotor faces.

Think of a clock...in order for the rotor to finish pointing at 1 a clock, the rotor would have to initially be pointed at 11 a clock when the distributor gear is first into contact with the camshaft gear

Mike, some comments. Remember that the crank turns twice as fast as the cam. So at TDC you either have both valves closed and the one just having closed is the INTAKE. Or if you're not on the compression stroke, you'll still be at TDC, but both valves very slightly open and the valve closing is the EXHAUST. Forget about BDC

About the distributor, it doesn't matter where the rotor is pointing, as long as the cap has cyl 1 wire at that position. I always try to have rotor pointing forwards, just to make it easier to remember. Usually I start with the distributor body, because it can't with vacuum advance be turned in all directions, you have to find a position that gives room for turning a bit in each direction to adjust initial timing, then you install the cap, some can go on two ways, most only one way, then the wires (so as few as possible has to cross). When all that is done, then you know where the rotor has to point.

10-12 degrees is a good conservative number to start with.

quote:

Originally posted by 1Rocketship:
Hello Robbie; The "Kentucky Windage" line, made me chuckle.

Wonder how many know that phrase?

Pantera Doug thinks it's what a guy from Kentucky does after eating too much Chili! .

I learn sumtin' newz almost everyday? Odd though that 'fornians would know 'bout Kentucky? Where is that anyway? Is it a real place?

I do know that the Third Reich attempted to bottle the methane from human waste.

Of equal importance I'd 'recon?

Mike
You say you have a new distributor. I believe you have a roller cam that probably needs a steel or bronze gear. You need to be sure the distributor gear is correct for the cam or you will be doing this all over again very soon. Most if not all new or rebuilt distributors will have a cast iron gear that will not work with a steel cam and will ruin the cam gear most likely.
Good luck.
Forest

quote:

Originally posted by PanteraDoug:..\
I learn sumtin' newz almost everyday?...

While I think I have learned a LOT automotive related, there has been some eyeopening about other things.

It took me a while and google to get the "brown sugar" / LSD comment, but I still haven't figgered out the "fridge" referance

while "Kentucky Windage" is meant to be derugatory, it is actually implies impressive knowledge in the application of advance physics and mathmatics with out the add of devices

quote:

Originally posted by JFB #05177:

quote:

Originally posted by PanteraDoug:..\
I learn sumtin' newz almost everyday?...

While I think I have learned a LOT automotive related, there has been some eyeopening about other things.

It took me a while and google to get the "brown sugar" / LSD comment, but I still haven't figgered out the "fridge" referance

while "Kentucky Windage" is implied to be derugatory, it is actually implies impressive knowledge in the application of advance physics and mathmatics with out the add of devices

It was thought that LSD was stored on sugar cubes in the '60s. It was joked that if one was let's say, "one of the beautiful people" like Dick Shaun's character in "The Producers", that it might be significant to inform house guests that sugar cubes in the refrigerator, a.k.a., the "'frige", were not kept there to sweeten one's coffee?

...AND that hopefully "unknowing" people didn't have a "sweet tooth" in fear that if they took two or three sugar cubes in their coffee that they possibly may NEVER "come down"?



It was also "joked" in "Where the Buffalo Roam", by Hunter Thompson, that "Richard Nixon was seen doing cannonballs in the hotel swimming pool with "stewardess'" and that it was probably due to the fact that he took a "hit" of "brown LSD sugar cubes".

It was "rumored" that if left in the sun to turn "brown", the LSD had extra psychedelic "enhancements".


As far as being derogatory towards Kentucky, not necessarily so.



Now having said that, and acknowledging the fact that fortunately or unfortunately I am a native NY'er.

Snicker if you will, but in fact some of these sarcastic remarks that I make are in fact intended to be self defecating in a sense to give others a laugh, even if it is at my expense? Also attempting to apply the sarcasm in a manor of Hunter Thompson without his grace or license often gets me in deep do-do too. I'm in it to begin with most of the time so I figure what the heck?


There was in fact once a "weighted map of the world" published by the New Yorker magazine which showed NYC as approximately 99% of the world and the rest of the entire world at 1%.

It was intended as again, a self-defecating joke about NYC and the New Yorker magazine itself.



Now for lack of a better term, there is a friction, between east coast "guys" and "west" coast guys.

Most of the time it is just stated as "the right coast, and the wrong coast", and that's the end of it.


Now having said all of this, and admitting it all, that it is in fact INTENDED as a joke where people can laugh or even laugh at me, sometimes there are just bad jokes made.


IF that is the case, then I offer my apologies. I am sorry Mrs.Teacher, I will never speak in your class again.

The distributor drive gear is the same as the one that was on the old diz, plus, there were 2 or 3 extra distributor gears and pins that came with the bag of goodies I got with the car from Roger. All are identical in every way.

I think if one were made from a different material, or cast and not steel, I'd notice the difference.

Also, the old cam gear that came out showed perfect wear. I believe they were all Mallory gears.

quote:

some of these sarcastic remarks that I make are in fact intended to be self defecating in a sense to give others a laugh

Trust me. They do. Perhaps more so than you'd intended.

FWIW, I believe the term you're looking for is "self-deprecating". Defecating is something entirely different.

quote:

Originally posted by MarsRed:

quote:

some of these sarcastic remarks that I make are in fact intended to be self defecating in a sense to give others a laugh

Trust me. They do. Perhaps more so than you'd intended.

FWIW, I believe the term you're looking for is "self-deprecating". Defecating is something entirely different.

Perhaps, but perhaps that's even a Freudian slip that is pretty funny?

I can't talk about this here anymore. I promised Mrs. Teacher I'd be quite and keep my self amusing quips to myself?

Actually I think self defecating seems more appropriate to me? It's funnier?

Congrats PanteraDoug, you did it again, you managed to totally derail a thread, and turn it into facebook for old geezers. (The "congrats" was meant as sarcasm)

George, are you reading this? Could we maybe agree there's a place for all these ramblings and funny and quaint inputs, and stories from the old days etc., and that place is Alejandro's Neighbourhood Pub, the Socializing Forums. And that the others, or at least the Technical Forum is kept free from that?

When I from time to time post a question on the Technical Forums, I'd like technical advice, and not see my thread being hi-jacked by inputs that have nothing to do with my problem.

I've been on this Forum for almost a decade, and IMHO it's gone seriously downhill in the last year, due to the above.

?